KENNETH ZIERER, M.D. appears in the CMS NPPES registry as a Gastroenterology Physician provider holding M.D. credentials at 71 UNION AVE STE 201, RUTHERFORD, NJ, 07070, with a listed phone of (201) 842-0020. NPI 1417978883 was issued on 07/21/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what ZIERER most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

Medicare Part D records for calendar year 2023 show 1,191 prescription claims written by this provider, covering 275 Medicare beneficiaries and totaling roughly $339K in drug spend, split 8% brand-name and 92% generic by claim count. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 100/100 for the 2023 performance year, compared with the national average of 83.1.

Gastroenterology Physician is a mid-sized specialty nationwide, with 16,567 enrolled providers across 54 states and an average of 833 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline. Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist — always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.